JP5321182B2 - Heat sink substrate and housing - Google Patents

Description

  The present invention relates to an electronic circuit board (board) used by being connected so as to be subordinate to an electronic circuit board (backplane) serving as a backbone. In particular, the present invention relates to a board that includes a large heat sink and is connected to the backplane together with the heat sink.

  In a device that takes a form in which a board is connected to a backplane, a guide rail is generally installed in the housing of the device for insertion of the board, and is perpendicular to the edge connected to the backplane of the board. As both ends are guided by the guide rail, the board is guided and connected to the connector on the backplane side.

  In a generally created backplane, the connector mounting position has a slight error, and therefore it is necessary to provide a gap for absorbing this between the board and the guide rail. Accordingly, the board is supported by the guide rail until it is connected, but when the connectors are connected, a part of the board is not supported by the guide rail, and a part of the load is held in a state where the connector supports it.

  By the way, when an electronic calculation semiconductor represented by a CPU (hereinafter referred to as a semiconductor chip) is used, it is necessary to take measures against heat according to the amount of heat generated. The heat radiation method is generally a method in which heat is transferred and radiated to the atmosphere by a heat sink using a metal (aluminum or copper) having excellent thermal conductivity, and a fan is attached and used as necessary.

  The capacity of the heat sink correlates with the air contact area of the heat sink and the air volume of the fan. Therefore, generally, as the heat generation amount of the semiconductor chip increases, the heat sink becomes larger, and the fan is selected to have a large size or high rotation. .

  If a high-rotation fan is used, the heat sink can be small, but in this case, the noise of the fan increases. Also, when using a large fan, it is possible to use a small heat sink, but it is difficult to install a large fan in the current situation where high density and high speed of electronic circuits are required.

  On the other hand, if a large heat sink is used, a fan is not used or a small fan is used at best. However, when a board with such a heat sink is connected to the backplane, the load on the connector increases due to the weight of the large heat sink, making it difficult to support the heat sink load, possibly causing poor contact or damage to the connector. The problem that the property becomes high arises.

  Patent Document 1 attempts to solve the problem by reinforcing the periphery of the electronic circuit board with a structure using a material having sufficient strength to support a heat sink such as metal and connecting the heat sink to the structure. However, according to this technique, it is necessary to use a structure made of a specific material, which is inevitably expensive.

JP 2001-77255 A

  The present invention has been made in view of the above problems, and an object thereof is to prevent an excessive load from being applied to the vicinity of a connector when a board using a large heat sink is attached to a backplane. In addition, an excessive load near the connector is prevented regardless of the material.

In order to solve the above-mentioned problem, the invention described in claim 1 is an electronic circuit board that is used by being guided by a guide rail and connected to another electronic circuit board (backplane), and is an electronic circuit board on which a semiconductor chip is mounted. In a substrate with a heat sink comprising a circuit board main body and a heat sink for dissipating heat generated from the semiconductor chip, the electronic circuit board and the other electronic circuit board are connected by a connector, and the electronic circuit board main body has a plurality of through holes The heat sink has a guide pin, the guide pin is inserted into the through hole, and the substrate main body and the heat sink are fixed, and the diameter of the through hole is the guide. is configured larger than the diameter of the pin, have a gap between the edge of the guide pin and the through hole, the heat sink is inserted into the guide rail, wherein the heat Sink in which is so supported by the guide rail.

  According to the present invention, since there is a gap between the edge of the guide pin and the through hole, even when the substrate with heat sink (board) and the backplane are connected, the board is guided by falling downward due to the weight of the heat sink. It is possible to prevent the load from being applied to the connector by continuously contacting the rail and supporting the load of the heat sink by the guide rail installed in the housing or the like.

  In addition, according to the first aspect of the present invention, even when there are various errors between the board and the backplane, these errors can be absorbed by this gap. Examples of these errors include errors in the mounting position of the connector installed on the backplane, manufacturing errors in the heat sink, manufacturing errors in the guide pin mounting position, and the like.

According to a second aspect of the present invention, a width of the heat sink with respect to a direction perpendicular to the guide rails facing each other is smaller than a width between the guide rails facing each other. For this reason, the board with a heat sink can pass between the guide rails, and when the heat sink falls down due to its own weight, the load of the heat sink can be supported by the lower guide rails.

  According to a third aspect of the present invention, there is provided an urging means for pressing the substrate body and the heat sink together. A spring or the like can be used as the biasing means. If the force to attach the board is greater than necessary, the board will be bent abnormally. Further, when the frictional force between the chip surface and the heat sink is larger than the weight of the heat sink, when the board is connected to the backplane connector, it floats together with the board and the load is applied to the backplane connector. According to the third aspect of the present invention, since the substrate body and the heat sink are pressed against each other by the biasing means such as a spring, it is possible to hold the substrate body with a necessary force, and the occurrence of the above problem can be prevented.

Next, the invention described in claim 4 relates to a housing including the board of claim 1, and an electronic circuit board with a heat sink, another electronic circuit board (backplane) connecting the board, and the heat sink. And a guide rail for guiding the attached electronic circuit board and connecting the two, wherein the electronic circuit board and the other electronic circuit board are connected by a connector, and the heat sink is connected to the guide. inserted into the rails, the heat sink is supported by said guide rail, an electronic circuit board with the heat sink, comprising an electronic circuit board body provided with a semiconductor chip, a heat sink for radiating heat generated in this semiconductor chip, an electronic circuit board The main body has a plurality of through holes, and the heat sink has a guide pin. The substrate body and the heat sink are fixed by being inserted into the through holes, and the diameter of the through hole is larger than the diameter of the guide pin, and there is a gap between the guide pin and the edge of the through hole. It is made to have.

  According to the present invention, even when a large heat sink is used, the load of this heat sink can be supported by the guide rail, so that an excessive load is not applied near the connector and the board is attached to the backplane. Can do.

The schematic diagram which shows one example of embodiment of this invention BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the case where a U-shaped case is attached in embodiment of this invention, (a) The perspective view seen from the fin side of the heat sink, (b) The perspective view seen from the board side

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the board with a heat sink of the present invention comprises a board body 2 and a heat sink 1. The heat sink 1 is provided with four guide pins 11, and the board body 2 is provided with four through holes 21 corresponding to the guide pins 11. The diameters of the through holes 21 are larger than the diameter of the guide pins 11, and are configured to have a gap between the guide pins 11 and the edges of the through holes 21. The board body 2 is provided with a chip that requires heat dissipation on the heat sink 1 side. When the guide pin 11 is inserted into the through hole 21 and fixed by means such as a bolt, for example, a degree of freedom corresponding to the gap between the guide pin 11 and the through hole 21 can be provided in the plane direction of the board body 2.

  The board to which the heat sink 1 is fixed in this way is inserted into two guide rails 3 arranged in the vertical direction, and the guide rail 3 guides the board in the insertion direction of the housing (in the direction of the arrow A). To use). The guide rail 3 is installed in the housing, and it is desirable that the guide rail 3 be installed so as to be slightly wider than the width of the heat sink 1 to provide a gap. However, it is possible to provide only a load of the heat sink by providing a flat support member instead of the guide rail.

  Note that the vertical gap between the guide pin 11 and the through hole 21 takes into account an error in the mounting position of the connector installed on the backplane, an error in manufacturing the heat sink, and an error in manufacturing the mounting position of the guide pin. However, if there is an unnecessarily large clearance in the front-rear direction, there is a problem that when the connector 22 of the board main body 2 is inserted into the connector on the backplane, the connection cannot be made sufficiently, or the connector is easily disconnected. Therefore, it is desirable that the through hole 21 has an elliptical shape that is long in the direction (arrow B direction) perpendicular to the insertion direction (arrow A direction) with respect to the guide pin.

  However, when the above-mentioned gap affects the accuracy in connection, such as when the number of pins of the connector is large, only the vicinity of the connector 22 can be separately guided and connected using a separate alignment pin or the like. Or it can also guide by providing a guide rail for board body 2 which is not illustrated separately. Also, if a horizontal gap is provided in the guide rail 3 of the heat sink, the board body 2 is connected at an optimum place when the connector is connected, and the horizontal error of the connector mounting position on the backplane due to the heat sink 1 following it. It can correspond to.

In this example, the fins of the heat sink 1 are arranged in the horizontal direction, and it is considered that forced intake or exhaust is performed from the front of the board. In this case, by covering the entire fin-side surface of the heat sink 1 with a flat plate-shaped member, the air flow path is limited to the periphery of the fin, and the heat dissipation performance of the heat sink 1 can be enhanced. As an example, in FIG. 2, the fins are covered by placing the heat sink 1 in a U-shaped case 4.

  In addition, since the heat sink is large, a large force is applied when the fin portion is grasped. As described above, it is possible to improve the safety during work by covering the periphery of the fin and preventing the end of the fin from being exposed.

  As described above, in this example, the fin angle of the heat sink 1 is shown as horizontal, but when the airflow is hindered by the backplane or when natural air cooling is used, the fins are arranged so that they have an angle. Heat can be dissipated by avoiding the backplane or generating a backward flow by an updraft caused by natural air cooling.

  Next, as the material of the guide rail 3, when the board 2 is frequently inserted and removed, it is desirable to select a polymer material with less friction. However, when the board is not inserted and removed, heat conduction such as aluminum is preferable. By using a good material, the heat dissipation can be improved by transferring the heat of the heat sink 1 to the housing.

  When installing the front panel, if the front panel is attached to the heat sink 1 instead of the board, the adjacent front panels can be arranged linearly regardless of the board mounting height deviation, Heat can also be radiated from the front panel.

  Further, the front panel can be subjected to a surface treatment such as alumite treatment to enhance the heat radiation, and the heat radiation can be enhanced by forming the front panel in a heat sink shape.

  The heat sink mounting structure according to the present invention can be mounted on a board provided with a necessary large heat sink without applying a load to the backplane connector, and is useful for an electronic device whose performance and density are increasing. .

11 ... heat sink 12 ... guide pin 21 ... board 22 ... hole 23 ... connector 31 ... guide rail 41 ... heat sink case

Claims (4)

An electronic circuit board used by being guided by a guide rail and connected to another electronic circuit board (backplane),
In a substrate with a heat sink that includes an electronic circuit board body on which a semiconductor chip is mounted and a heat sink that dissipates heat generated by the semiconductor chip,
The electronic circuit board and the other electronic circuit board are connected by a connector,
The electronic circuit board main body has a plurality of through holes, and the heat sink has guide pins, the guide pins are inserted into the through holes, and the board main body and the heat sink are fixed.
And the diameter of the through hole is configured larger than the diameter of the guide pin, have a gap between the edge of the guide pin and the through hole,
The heat sink is inserted into the guide rail, the heat sink substrate with the heat sink is characterized in that it is supported by the guide rail. 2. The substrate with a heat sink according to claim 1, wherein a width of the heat sink with respect to a direction perpendicular to the guide rails facing each other is smaller than a width between the guide rails facing each other . The substrate with a heat sink according to claim 1, further comprising an urging unit that presses the substrate body and the heat sink together. A housing comprising an electronic circuit board with a heat sink, another electronic circuit board (backplane) to which the board is connected, and a guide rail that guides the electronic circuit board with the heat sink and connects the two. And
The electronic circuit board and the other electronic circuit board are connected by a connector,
The heat sink is inserted into the guide rail, and the heat sink is supported by the guide rail;
The electronic circuit board with a heat sink includes an electronic circuit board body on which a semiconductor chip is mounted, and a heat sink that dissipates heat generated from the semiconductor chip. The electronic circuit board body has a plurality of through holes, and the heat sink. Has a guide pin, the guide pin is inserted into the through hole, and the substrate body and the heat sink are fixed.
And the diameter of the said through-hole is comprised larger than the diameter of the said guide pin, and it has a clearance gap between the edge of a guide pin and a through-hole.

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